Introduction Unprotected intercourse after oral emergency contraception (EC) significantly increases pregnancy risk. This underlies the importance of promptly starting effective, ongoing contraception – known as ‘quick starting.’ However, theoretical concern exists that quick starting might interact with EC or hormonal contraception (HC) potentially causing adverse side effects.
Methods A systematic review was conducted, evaluating quick starting HC after oral EC (levonorgestrel 1.5mg [LNG] or ulipristal acetate 30mg [UPA]). PubMed, EMBASE, The Cochrane Library, ICTRP, ClinicalTrials.gov and relevant reference lists were searched in February 2016. A lack of comparable studies prevented meta-analysis.
Results Three randomised controlled trials were identified. Two biomedical studies suggested HC action was unaffected by quick starting after UPA; one study examined ovarian quiescence (OR: 1.27; 95% CI 0.51 to 3.18) while taking combined oral contraception (COC). Another assessed cervical mucus impenetrability (OR: 0.76; 95% CI 0.27 to 2.13) while taking progestogen-only pills (POP). Quick starting POP reduced the ability of UPA to delay ovulation (OR: 0.04; 95% CI 0.01 to 0.37). Side effects (OR: 1.22; 95% CI 0.48 to 3.12) and unscheduled bleeding (OR: 0.53; 95% CI 0.16 to 1.81) were unaffected by quick starting COC after UPA. Another study reported higher self-reported contraceptive use at eight weeks among women quick starting POP after LNG, compared with women given LNG alone (OR: 6.73; 95% CI 2.14 to 21.20).
Discussion Limited evidence suggests quick starting HC after UPA does not reduce HC efficacy, however it reduces UPA efficacy. Consequently, women should delay starting HC after UPA.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.